Question: Simplify the following expression: $k = \dfrac{7}{3a} - \dfrac{1}{2a}$
Solution: In order to subtract expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $3a$ and $2a$ $\lcm(3a, 2a) = 6a$ $ k = \dfrac{2}{2} \cdot \dfrac{7}{3a} - \dfrac{3}{3} \cdot \dfrac{1}{2a} $ $k = \dfrac{14}{6a} - \dfrac{3}{6a}$ $k = \dfrac{14 -3}{6a}$ $k = \dfrac{11}{6a}$